Improving the efficiency of electrical drives control is of great importance in modern industry and common life. Electrical drives of different types are used in large numbers in factories, in transport, in laboratories, offices, private homes and so forth. Studies indicate that a typical family in the United States owns over 60 motors which make life more comfortable and efficient. Production of electrical motors is estimated in the millions per day. Such enormous use of electrical motors underscores the problem of effective control of electrical drives.
Control of electrical drives begins by determining the rotor position and speed. There are several ways to determine such parameters. First, the position of the rotor may be determined by an array of phototransistors and a special shutter coupled to the rotor shaft, or by using Hall-effect sensors. Such systems are described in T. Kenjo, Electrical Motors and Their Controls, Oxford University Press, (1994), 176 pp. Second, the speed signal may be obtained by using a small permanent magnet tachometer generator, attached to the drive, or by using magnetic or optical sensors generating pulses for each angular increment of the rotor. Such systems are described in W. Leonhard, Control of Electrical Drives, 2.sup.nd ed., Springer (1966), 420 pp. Third, a resolver may determine the position of the rotor by a two-phase (sine/cosine) signal at a carrier frequency modulated sinusoidally by the rotation of the rotor. Such a system is described in J. R. Hendershot, Jr. and T. Miller, Design of Brushless Permanent-Magnet Motors, Magna Physics Publishing (1994), p. 1-19. However, all these methods have many disadvantages, such as the inability to determine the position of the rotor with high accuracy, the necessity to use different sensors with all auxiliary systems enabling their operations, the lack of a unified approach to the rotor position and speed determining, and the like.
Existing methods of control vary essentially for the regular and stepping motors. For stepping motors, the number and position of steps is determined by the construction and cannot be controlled electronically. Stepping motors are described in T. Kenjo, A. Sugavara, Stepping Motors and Their Microprocessor Controls, 2.sup.nd Edition, Clarendon Press (1994), 280 pp. Attempts to solve this problem using closed loops with selective amplifiers and frequency dividers have not been completely successful, and also have resulted in rigid structures with inefficient methods of control such as direct mechanical or electromagnetic action on the rotor. Such systems are described in A. Abdukayumov, M. Rakov, Electromechanical Phase Multi-Stable Element, Patent USSR No. 275529, Bulletin No. 22 (1970), and A. Abdukayumov, M. Rakov, Electromechanical Phase Multi-Stable Element, USSR Patent No. 315274, Bulletin No. 28 (1971). Other systems use structures of a converter of a code in the angular position of an axis of the rotor. Such systems are described in A. Abdukayumov, V. Pogribnoi, M. Rakov, Converter of the Code in the Angle, USSR Patent No. 391725, Bulletin No. 31 (1973) and A. Kmet, V. Pogribnoi, M. Rakov, Converter of the Code in the Angle, USSR Patent No. 394749, Bulletin No. 34 (1973). These systems are complex and have only a rather limited number of stable states (steps). Because of these disadvantages, such systems have not been further applied to electrical motors. It is desired to create a more effective general method of electrical drive control.